Life cycle assessment of building insulation materials across Italian climatic zones: Global warming potential vs net present value

This study presents a comparative Life Cycle Assessment (LCA) and economic analysis of three insulation materials — expanded polystyrene (EPS), rockwool, and hemp — applied to residential buildings in four Italian climatic zones. Environmental impact is evaluated through Global Warming Potential (GWP), while economic performance is assessed via Net Present Value (NPV) over the life cycle. An automated simulation workflow using EnergyPlus enables the assessment of multiple configurations by varying material properties, thickness, and climatic conditions. Results highlight trade-offs between environmental and economic performance. Compliance with regulatory thresholds can be achieved with varying insulation thickness depending on climate and material. Bio-based solutions like hemp may offer greater environmental benefits, although in most climates they require incentives to be cost-effective. This integrated approach provides useful insights for designers, policymakers, and stakeholders aiming to balance cost-effectiveness with sustainability in building retrofit and construction.